Contact Activated Lancet Device

ABSTRACT

A lancet device including a housing and a lancet structure having a puncturing element. The lancet structure disposed within the housing and adapted for movement between a retaining or pre-actuated position wherein the puncturing element is retained within the housing, and a puncturing position wherein the puncturing element extends through a forward end of the housing. The lancet device includes a drive spring disposed within the housing for biasing the lancet structure toward the puncturing position, and a retaining hub retaining the lancet structure in the retracted position against the bias of the drive spring. The retaining hub includes a pivotal lever in interference engagement with the lancet structure. An actuator within the housing pivots the lever, thereby moving the lancet structure toward the rearward end of the housing to at least partially compress the drive spring, and releasing the lever from interference engagement with the lancet structure.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.12/815,067 filed Jun. 14, 2010 entitled “Contact Activated LancetDevice”, which is a divisional application of U.S. application Ser. No.11/123,849 filed May 6, 2005 entitled “Contact Activated Lancet Device”(now U.S. Pat. No. 9,380,975), which claims priority to U.S. ProvisionalApplication Nos. 60/569,424 filed May 7, 2004, 60/631,846 filed Nov. 30,2004, 60/631,795 filed Nov. 30, 2004, and 60/669,276 filed Apr. 7, 2005,the entire disclosures of each of which are herein incorporated byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to medical puncturing devices,commonly referred to as lancets, which are used to take blood samplesfrom patients and, more specifically, to a lancet device that isdesigned for ease of use with activation achieved during contact of thedevice in normal use.

Description of Related Art

Lancet devices are used in the medical field for puncturing the skin ofa patient to obtain a capillary blood sample from the patient. Certaindiseases, such as diabetes, require that the patient's blood be testedon a regular basis to monitor, for example, the patient's blood sugarlevels. Additionally, test kits, such as cholesterol test kits, oftenrequire a blood sample for analysis. The blood collection procedureusually involves pricking a finger or other suitable body part in orderto obtain the blood sample. Typically, the amount of blood needed forsuch tests is relatively small and a small puncture wound or incisionnormally provides a sufficient amount of blood for these tests.

Various lancet devices are commercially available to hospitals, clinics,doctors' offices, and the like, as well as to individual consumers. Suchdevices typically include a sharp-pointed member such as a needle, or asharp-edged member such as a blade, that is used to make a quickpuncture wound or incision in the patient's skin in order to provide asmall outflow of blood. It is often physiologically and psychologicallydifficult for many people to prick their own finger with a hand-heldneedle or blade. As a result, lancet devices have evolved into automaticdevices that puncture or cut the skin of the patient upon the actuationof a triggering mechanism. In some devices, the needle or blade is keptin a standby position until it is triggered by the user, who may be amedical professional in charge of drawing blood from the patient, or thepatient himself or herself. Upon triggering, the needle or bladepunctures or cuts the skin of the patient, for example on the finger.Often, a spring is incorporated into the device to provide the“automatic” force necessary to puncture or cut the skin of the patient.

It is of the utmost importance in the medical field that such medicalpuncturing devices or lancets are in a sterile condition before use.Today, generally without exception, medical puncturing devices orlancets are manufactured and packaged in a sterilized condition beforethey are distributed to medical professionals and members of the publicwho have a need for such devices. The sterile packaging maintains thesterility of the device, ensuring that the surrounding environment doesnot contaminate it until use. In addition, it is also of increasingimportance that the user or another person does not come into contactwith the needle or blade after use of the device. With the concern overblood-borne diseases, medical professionals are required to take greatcare with medical devices that come into contact with the blood ofpatients. Thus, an important aspect of lancet design involves preventingthe needle or blade of the device from wounding the user or anotherperson after the blood sample is drawn from the patient. Once used, theneedle or blade should be shielded to prevent the needle or blade fromwounding the user or another person handling the device. Moreover, thelancet device should be disposable to eliminate the chances of diseasetransmission due to the needle or blade being used on more than oneperson. In this regard, the lancet device should ideally be designed forone firing, and have safety features to prevent reuse.

Advances have been made in recent years to increase safety in operatingand handling used lancet devices. For example, lancet devices arecurrently available which are single shot devices that feature automaticejection and retraction of the puncturing or cutting element from andinto the device. Examples of such medical puncturing devices aredisclosed in U.S. Pat. Nos. 6,432,120; 6,248,120; 5,755,733; and5,540,709.

U.S. Pat. No. 6,432,120 to Teo discloses a lancet device that includes alancet holder which contains a spring-loaded lancet structure. Thespring-loaded lancet structure includes a single spring that effects theejection and retraction of a lancet needle upon the triggering of thestructure. U.S. Pat. No. 6,248,120 to Wyszogrodzki discloses a lancetdevice comprised of a housing, a shielding portion, a piston with apuncturing tip, and drive and return springs that eject and retract thepiston, respectively, upon the breakage of internal wing elements in thehousing. U.S. Pat. No. 5,755,733 to Morita discloses a lancet devicethat includes a combined holder and lancet structure. The lancetstructure includes a lancet member with a puncturing tip and acompressible spring member that causes the lancet member to puncture theskin of a patient upon actuation of a pair of actuating arms.

U.S. Pat. No. 5,540,709 to Ramel discloses a lancet device that includesa housing enclosing a slidable trigger, which is used to trigger acompressed spring that powers a piercing lancet member to pierce theskin of a patient. The housing includes a pair of internal fingers thatengage and hold the body of the lancet member, which are then releasedof engagement with the lancet member body by axial force applied by theuser to the slidable trigger. Other medical puncturing devices orlancets known in the art are disclosed in U.S. Pat. Nos. 4,869,249 and4,817,603. The devices disclosed in these references include a cap thatis used to protect a needle or to keep the needle sterile.

SUMMARY OF THE INVENTION

In view of the foregoing, a need generally exists in the medical fieldfor a medical puncturing device that is easy for a user to manipulateand use while ensuring sterility before use and safe and secure disposalafter use. Additionally, a need exists in the medical field for asimple, reliable, self-activating, and disposable medical puncturingdevice for use in collecting blood samples.

A lancet device in an embodiment of the invention generally includes ahousing and a lancet structure having a puncturing element, with thelancet structure disposed within the housing and adapted for movementbetween a retaining or pre-actuated position wherein the puncturingelement is retained within the housing, and a puncturing positionwherein the puncturing element extends through a forward end of thehousing. The lancet device further includes a drive spring for biasingthe lancet structure toward the puncturing position. The drive springmay be disposed between a rearward end of the housing and the lancetstructure, and may be a separate structure or may be integrally formedwith one or both of the housing and/or the lancet structure. The lancetdevice further includes a lever element pivotal about a fulcrumproviding interference engagement with the lancet structure andretaining the lancet structure in the retracted position against thebias of the drive spring. The lever element may include a retaining hubincluding a pivotal lever in interference engagement with the lancetstructure and pivotal about a fulcrum of the retaining hub. Movement ofthe housing and the retaining hub with respect to each other, such asaxial or longitudinal movement, causes the lever to pivot about afulcrum, thereby releasing the lever from interference engagement withthe lancet structure and, typically, moving the lancet structure towardthe rearward end of the housing to at least partially compress the drivespring. With the lancet structure released from the lever, the drivespring drives the lancet structure through the housing toward thepuncturing position.

The lever may include a shoulder in interference engagement with thelancet structure and a contact surface for engagement with an internalcontact within the housing. The housing may include an internal contacttherein for pivoting of the lever, which may be an integrally formed camsurface for cooperating engagement with the contact surface of thelever. The lever may be a class 1 type lever, with a pivoting point orfulcrum between the load element and the force element, such as asee-saw type of lever. Desirably, the lever is a wedge pivotally hingedto the retaining hub forming a pivot hinge defining the fulcrum forcooperative pivoting of the shoulder and the contact surface about thehinge or fulcrum. Moreover, the retaining hub may include an annularrim, with the lever pivotally hinged to the annular rim.

In a further embodiment of the invention, a lancet device includes ahousing and a lancet structure adapted for axial or longitudinalmovement through the housing between a pre-actuated position with apuncturing element of the lancet structure retained within the housingand a puncturing position with the puncturing element extending througha forward end of the housing. A drive spring biases the lancet structuretoward the puncturing position, and a retaining hub retains the lancetstructure in the pre-actuated position against the bias of the drivespring. The retaining hub includes a lever pivotal about a fulcrum, withthe lever in interference engagement with the lancet structure. Anactuator is adapted to pivot the lever about the fulcrum to release thelever from interference engagement with the lancet structure, therebypermitting the drive spring to drive the lancet structure to thepuncturing position.

The actuator may include an actuator element extending through and intothe housing, such as a push button element extending through a rearwardend of the housing which is axially movable with respect to the housingto cause the actuator element to pivot the lever about the fulcrum.Alternatively, the actuator may include an internal contact within thehousing such as an internal contact integrally formed within thehousing, such that axial movement of the housing toward the retaininghub causes the internal contact within the housing to pivot the leverabout the fulcrum.

Desirably, the lancet device further includes a shield extending throughthe forward end of the housing and axially or longitudinally movablewith respect to the housing, with the retaining hub adjacent therearward end of the shield. The lancet structure may be retained by theretaining hub at the rearward end of the shield. In this manner,relative axial or longitudinal movement of the rearward end of theshield and the rearward end of the housing toward each other causes theinternal contact within the housing to pivot the lever of the retaininghub, thereby actuating the device by releasing the interferenceengagement between the lever and the lancet structure. Desirably, thelancet structure and the shield include corresponding guiding surfacesfor guiding the lancet structure axially or longitudinally through theshield.

In a further embodiment, a lancet device includes a housing having arearward end and a forward end having an opening extending therethrough,and a shield movable through the opening of the forward end of thehousing, such as axially or longitudinally, with the shield including alever element, such as a retaining hub adjacent a rearward end thereof,including a pivotal lever. A lancet structure with a puncturing elementis disposed within the housing. The lancet structure is in interferenceengagement with the lever of the retaining hub at the rearward end ofthe shield, and is adapted for axial or longitudinal movement between aretaining or pre-actuated position with the puncturing element disposedwithin the housing, and a puncturing position with the puncturingelement extending through a forward end of the shield. A drive spring isdisposed between the housing and the lancet structure for biasing thelancet structure against the lever of the retaining hub, with theinterference engagement between the lever and the lancet structuremaintaining the lancet structure in the retaining or pre-actuatedposition. Axial or longitudinal movement of the shield toward therearward end of the housing causes an internal contact within thehousing to engage the lever of the retaining hub, thereby causingpivotal movement of the lever to release the interference engagementbetween the lever and the lancet structure. The drive spring maythereafter drive the lancet structure axially or longitudinally throughthe shield toward the puncturing position.

The retaining hub desirably includes an annular rim, which may beseparate from and retained within the rearward end of the shield, withat least one lever pivotally supported on the annular rim. Moredesirably, a pair of levers are pivotally supported on opposing sides ofthe annular rim. The lever may further include a shoulder forinterference engagement with the lancet structure, as well as a contactsurface for engagement with the internal contact of the housing to causethe lever to pivot, thereby releasing the lancet structure frominterference engagement with the shoulder. For example, the internalcontact of the housing may include an integrally formed cam surface forcooperating engagement with the contact surface of the lever. The levermay be in the form of a wedge pivotally hinged to the retaining hubforming a pivot hinge for cooperative pivoting of the shoulder and thecontact surface.

The lancet device may further include a retraction spring for retractingthe lancet structure within the shield after the drive spring drives thelancet structure axially through the shield toward the puncturingposition. For example, the retraction spring may be a compression springpositioned within the forward end of the shield for compression betweenthe lancet structure and the forward end of the shield. The biasingforce of the compression spring between the forward end of the shieldand the lancet structure should exceed the biasing force of the drivespring between the rearward end of the housing and the lancet structureafter the drive spring drives the lancet device to the puncturingposition. In this manner, the retraction spring may retract the lancetstructure within the shield and/or the housing, thereby maintaining thepuncturing element therein. The shield and housing may further includelocking structure extending therebetween for maintaining the shield infixed relation to the housing after the drive spring drives the lancetstructure through the shield toward the puncturing position.

In yet a further embodiment, an improved lancet device includes ahousing and a lancet axially or longitudinally movable within thehousing and retained within the housing against a bias of a drive springwhich biases the lancet toward a puncturing position in which apuncturing element extends through a forward end of the housing. Theimproved lancet device includes a retaining hub, such as an annularstructure, having at least one lever in interference engagement with thelancet for retaining the lancet within the housing against the bias ofthe drive spring, with the lever being pivotal about a fulcrum. Pivotingof the lever about the fulcrum releases the lancet from interferenceengagement with the lever to permit the drive spring to drive the lancetaxially or longitudinally toward the puncturing position. The lever andfulcrum may be provided on one side of a plane dissecting the retaininghub at a cross section to an axis defined by the lancet.

In one variation of this embodiment, axial or longitudinal movement ofthe housing and the retaining hub with respect to each other causes aninternal contact within the housing to pivot the lever about thefulcrum. This may be accomplished through a shield extending through aforward end of the housing and axially or longitudinally moveable withrespect to the housing, with the retaining hub adjacent a rearward endof the shield. At least a portion of the lancet is axially orlongitudinally moveable through the shield and the retaining hub uponrelease of the lancet from interference engagement with the lever. In afurther variation, an actuator having an actuation element extendsthrough and into the housing, desirably through the rearward end of thehousing. Movement of the actuation element with respect to the housingcauses the actuation element to pivot the lever about the fulcrum. Inyet a further variation, the retaining hub may be unitary with theshield, and may be an annular structure.

A further embodiment provides an improved method of retaining a lancetstructure in a pre-actuated position within a housing against the biasof a drive spring by providing a retaining hub in the form of an annularrim including a lever in interference engagement with the lancetstructure. The lever is pivotal about a fulcrum, such that pivoting ofthe lever about the fulcrum releases the interference engagement betweenthe lever and the lancet structure, permitting the drive spring to drivethe lancet structure toward a puncturing position with a puncturingelement extending through a forward end of the housing.

Yet a further embodiment provides a method of actuating a lancet device.The method includes providing a lancet device comprising a housing, alancet structure disposed within the housing and including a puncturingelement retained within the housing, a drive spring biased against thelancet structure, such as between a rearward end of the housing and thelancet structure, and a retaining hub retaining the lancet structurewithin the housing against the bias of the drive spring through apivotal lever in interference engagement with the lancet structure. Toactuate the device, the lever is contacted with an actuator to pivot thelever, thereby sequentially causing the lancet structure to move towardthe rearward end of the housing to compress the drive spring andreleasing the interference engagement between the lever and the lancetstructure. This release causes the drive spring to drive the lancetstructure axially toward a puncturing position wherein the puncturingelement extends through a forward end of the housing. Other embodimentswhere the drive spring is constrained from further compression are alsocontemplated. For example, the drive spring may reach its solid heightand not permit further compression while still allowing movement of theretaining hub with respect to the housing as well as release ofinterference engagement between the lever and the lancet structure.

The actuator desirably includes an internal contact within the housing,with the contacting step involving axially or longitudinally displacingthe housing and the retaining hub toward each other to cause theinternal contact of the housing to pivot the lever. Moreover, the lancetdevice may further include a shield extending through the forward end ofthe housing and axially movable with respect to the housing, with theretaining hub adjacent the rearward end of the shield for retaining thelancet structure within the housing against the bias of the drivespring. In such an embodiment, the method further includes adisplacement step involving axially or longitudinally displacing therearward end of the shield and the rearward end of the housing relativeto each other to cause the contacting step. For example, thedisplacement step may involve applying external pressure between aforward end of the shield and the rearward end of the housing. Also, thelever may include a shoulder in interference engagement with the lancetstructure and a contact surface for engagement with the internal contactof the housing. In this manner, the contacting step involves engagingthe internal contact of the housing with the contact surface of thelever to pivot the lever.

Further, the retaining hub may include an annular rim with the leverpivotally hinged to the annular rim such that the shoulder extendsradially inward of the annular rim and the contact surface is at anexternal perimeter of the annular rim. In this manner, the contactingstep involves engaging the internal contact of the housing with thecontact surface of the lever at an external perimeter of the annularrim, thereby pivoting the lever by tipping the contact surface and theshoulder to release the lancet structure through the annular rim andthrough the shield.

The method may involve a further step of retracting the puncturingelement within the housing after the puncturing element reaches thepuncturing position. In particular, the lancet device may furtherinclude a compression spring positioned within the forward end of theshield. The retraction step involves compressing the compression springbetween the lancet structure and the forward end of the shield throughthe bias of the drive spring and thereafter relaxing the compressionspring. In an embodiment of the invention, the biasing force of thecompression spring between the forward end of the shield and the lancetstructure in a relaxed state exceeds the biasing force of the drivespring between the rearward end of the housing and the lancet structureafter the drive spring drives the lancet device to the puncturingposition. Accordingly, the puncturing element is retracted within theshield, thereby maintaining the lancet structure within the housing.

Further details and advantages will become apparent from the followingdetailed description when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of a lancet device in accordance with anembodiment of the present invention.

FIG. 2 is perspective view of the lancet device of FIG. 1 showing theprotective cover separated from the body of the lancet device.

FIG. 3 is an exploded perspective view of the lancet device of FIG. 1.

FIG. 4A is a bottom perspective view of the main body of the housing inan embodiment of the present invention.

FIGS. 4B and 4C are top perspective views of the main body of thehousing of FIG. 4A.

FIGS. 4D and 4E are opposing sectional views of the main body as shownin FIG. 4C.

FIG. 5A is a bottom perspective view of the rear cap of the housing inan embodiment of the present invention.

FIGS. 5B and 5C are opposing sectional views of the rear cap as shown inFIG. 5A.

FIG. 5D is a top perspective view of the rear cap of the housing of FIG.5A.

FIG. 5E is a sectional view of the rear cap as shown in FIG. 5D.

FIG. 6A is a bottom perspective view of the shield in an embodiment ofthe present invention.

FIGS. 6B and 6C are opposing sectional views of the shield as shown inFIG. 6A.

FIG. 6D is a top perspective view of the shield of FIG. 6A.

FIGS. 6E and 6F are opposing sectional views of the shield as shown inFIG. 6D.

FIG. 7A is a top perspective view of the lancet structure in anembodiment of the present invention including an integrally molded coverpost portion.

FIGS. 7B and 7C are opposing sectional views of the lancet structure asshown in FIG. 7A.

FIG. 7D is a bottom perspective view of the lancet structure of FIG. 7A.

FIG. 7E is a sectional view of the lancet structure as shown in FIG. 7D.

FIG. 8A is a top perspective view of the retaining hub in an embodimentof the present invention.

FIG. 8B is a bottom perspective view of the retaining hub of FIG. 8A.

FIG. 8C is a sectional view of the lancet structure as shown in FIG. 8B.

FIG. 8D is a cross-sectional view of the lancet structure as shown inFIG. 8B.

FIG. 8E is a top perspective view of a retaining hub in an alternateembodiment.

FIG. 9A is a bottom perspective view of the tab member in an embodimentof the present invention.

FIG. 9B is a top perspective view of the tab member of FIG. 9A.

FIGS. 9C-9F are opposing sectional views of the tab member as shown inFIGS. 9A-9B.

FIG. 10 is an exploded perspective view of the shield and the retaininghub with the lancet structure.

FIGS. 11A and 11B are front and side perspective views of the lancetdevice of FIG. 1.

FIG. 11C is a cross-sectional view of the lancet device taken along lineB-B of FIG. 11A.

FIG. 11D is a cross-sectional view of the lancet device taken along lineA-A of FIG. 11B.

FIG. 12 is a cross-sectional view of the lancet device of FIG. 11D withthe tab member removed and ready for use.

FIG. 13 is a cross-sectional view of the lancet device of FIG. 11D inuse, with the lever partially engaged.

FIGS. 14-15 are partial enlarged perspective views of the lancet deviceof FIG. 11D during use, with the rear cap removed.

FIG. 16 is a partial enlarged cut-away view of the lancet device in usein the position shown in FIG. 15.

FIG. 17 is a cross-sectional view of the lancet device of FIG. 11D inuse with the lancet structure in the puncturing position.

FIG. 18 is a cross-sectional view of the lancet device of FIG. 11D afteruse with the lancet structure in the final retracted position.

FIG. 19 is a cross-sectional view of a lancet device in an alternateembodiment of the present invention.

FIG. 20 is a perspective view of a further embodiment of a lancet deviceof the present invention.

FIGS. 21A-21C are bottom, side, and end views, respectively, of aretaining hub used in the lancet device shown in FIG. 53.

FIG. 22 is a perspective view of the retaining hub shown in FIGS.21A-21C.

FIGS. 23A-23D are longitudinal cross-sectional views of anotherembodiment of a medical puncturing device, showing the device prior toactuation and the operational steps for actuating the device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of the description hereinafter, the words “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”,“longitudinal”, “axial”, and like terms, if used, shall relate to theinvention, as it is oriented in the drawing figures. Additionally, theterm “distal” shall refer to the portion of the device closest thepuncture end and the term “proximal” shall refer to the portion of thedevice opposite the distal portion. It is to be understood that theinvention may assume many alternative variations and embodiments exceptwhere expressly specified to the contrary. It is also to be understoodthat the specific devices and embodiments illustrated in theaccompanying drawings and described herein are simply exemplaryembodiments of the invention.

Referring to FIGS. 1-3, a lancet device 10 according to an embodiment ofthe invention is generally shown. The lancet device 10 generallyincludes a housing 12, a shield 14 movably associated with the housing12, and a lancet structure 70 disposed therein. As will be discussed ingreater detail herein, the shield 14 is coaxially and movably associatedwith the housing 12, and is partially disposed within the housing 12,extending partially outward from the housing 12, with the lancetstructure 70 contained within and axially or longitudinally movablethrough the shield 14.

The housing 12 defines an elongated body, and is desirably formed with amain body 20 defining a distal or forward end portion 22, and a rear cap24 defining a proximal or rearward end portion 26. The interior portionof housing 12 is generally open defining internal cavity 28, whichinternal cavity 28 is closed at the rearward end through rear cap 24 andincludes an opening 30 through the forward end portion 22, through whichthe shield 14 extends, as will be discussed in further detail herein.Main body 20 and rear cap 24 may be integrally formed. Alternatively,main body 20 and rear cap 24 are separate elements which are affixed toeach other to form housing 12, which aids in assembly of lancet device10. FIGS. 4A-4E and 5A-5E depict the main body 20 and rear cap 24,respectively, in an example of such an embodiment. Main body 20 and rearcap 24 may be affixed together through an appropriate adhesive, or mayinclude inter-engaging structure providing a mechanical attachmenttherebetween, such as a frictional fit or a snap fit construction. Forexample, main body 20 may include an annular rim 31 defining an annulargroove 32, and rear cap 24 may include an annular protrusion 33 havingan annular lip 34 at mating surfaces thereof. When main body 20 and rearcap 24 are mated, annular protrusion 33 extends within the rear open endof main body 20, with annular lip 34 snap fitting over the annular rim31 and into the annular groove 32 of main body 20. It should berecognized that the arrangement of such elements is merely exemplary andmay be reversed, and it is contemplated that other inter-fittingengaging structure may be used to fit the main body 20 with the rear cap24. In an alternate embodiment, main body 20 and rear cap 24 may be anintegrally formed structure, and may therefore be molded together as onecomponent.

As shown in FIG. 11B, the generally elongated housing 12, defined bymain body 20 and rear cap 24, has opposed sides 35, 36, which may eachinclude a surface for accommodating a user's fingers, such as fingergrip indentations 37, 38. While two opposed finger grip indentations 37,38 are provided on the housing 12, it will be appreciated that only onefinger grip indentation 37 formed in the housing body 20 may be providedin accordance with the present invention. The finger grip indentations37 may be formed as concave depressions or recesses on the outer surfaceof the housing 12. Additionally, the rearward end 26 of housing 12, suchas the top surface of rear cap 24, may also include a surface foraccommodating a user's finger, such as rear finger grip indentation 39,which may also be formed as a concave depression or recess. The sidefinger grip indentations 37, 38 and the rear finger grip indentation 39provide ergonomically shaped surfaces that substantially conform to auser's fingertips to aid the user in manipulating the lancet device 10and using the lancet device 10 in a blood letting, drawing, orcollection procedure, and may provide multiple finger grip positions forthe user. The side finger grip indentations 37, 38 may be represented ascontours formed by a hyperbola as shown in FIG. 11B. The hyperbola, forexample, may include two asymptotes that intersect at a locationsubstantially coplanar with a plane of symmetry defining the mainhousing. Additionally, rear cap 24 may include a contour formed by ahyperbola, as shown in FIG. 11B. The housing 12 may further includestructure to generally improve the grip between the housing 12 and theuser's fingertips, such as a plurality of longitudinal ribs 40 andtroughs 41 extending along the housing 12 and integrally formed with thehousing 12, which may provide a visual and tactile cue to the user toinstruct the user where to place his or her fingertips. The housing 12may further include at least one and optionally two or more peripheralindentations 42 disposed at the forward end 22. In one particularembodiment, the lancet device may be constructed in accordance with thefeatures disclosed in Application No. 60/631,795 9filed Nov. 30, 2004,and entitled “Lancet Device” naming Bradley Wilkinson as inventor, theentirety of which is incorporated herein by reference thereto.

As noted above, the shield 14 extends outward from the opening 30through the forward end of the housing 12. As shown in FIGS. 6A-6F, theshield 14 is a generally cylindrical hollow structure defining a shieldbody 50 extending between a forward end 52 and a rearward end 54, anddefining an internal cavity 56 extending therethrough. The forward end52 of the shield body 50 defines a forward end wall 58 including aforward opening 60 therethrough, through which the puncturing elementextends when the lancet device 10 is actuated by the user, as will bediscussed in more detail herein. The forward end wall 58 generallydefines a small contact area about the distal opening 60 for contactingthe intended area on the user's body which is to be punctured by thepuncturing element. The reduced contact area may be made smaller (i.e.,reduced in area) by providing a plurality of peripheral indentations 62that are formed in the shield 14. The peripheral indentations 62 mayalso provide a target indicia to visually aid the user in aiming thelancet device 10 generally, and aiming the puncturing element of thelancet in particular, as will be discussed in greater detail. Theperipheral indentations 62 generally resemble the peripheralindentations 42 provided on the housing 12. The peripheral indentations42 are positioned around the perimeter of the shield 14 and may beequally spaced about the shield 14. The peripheral indentations 42enable the user to easily visually locate the approximate dischargepoint of the puncturing element, thereby improving the aimingcharacteristics of the lancet device 10 and ensuring optimal blood flowduring a skin puncturing operation.

As noted, the shield 14 is axially or longitudinally movable within thehousing 12. The shield 14 and housing 12 may therefore includecorresponding guiding surfaces for guiding the shield 14 through thehousing 12. For example, shield body 50 may include a pair oflongitudinal protrusions 63 extending along an outer surface thereof,forming guide channel 64 therebetween. Housing 12 may includecorresponding structure such as a guide tab 44 within the main body 20thereof for fitting within guide channel 64. Desirably, shield body 50includes a pair of guide channels 64 extending longitudinally alongopposing sides thereof, and housing 12 includes a pair of guide tabs 44on opposing inner surfaces of main body 20 corresponding to each of theguide channels 64. It is contemplated that the arrangement of the guidetabs and channels may be reversed, and other guiding surfaces may alsobe used. The guide tabs 44 and guide channels 64 ensure that the shieldbody 50 is properly aligned within housing 12, and provide for slidingaxial movement of the shield body 50 within the housing 12, anddesirably prevent or resist rotational movement. Additionally, shieldbody 50 may include a ledge 66 at the rearward end thereof, forinterference engagement with the top surface of guide tab 44 within mainbody 20 of housing 12. Alternatively or in addition thereto, shield body50 may include a forward shoulder 69 toward the forward end thereof, andmain body 20 of housing 12 may include a forward rim surface 48,providing interference engagement therebetween. Such interferinglyengaging structure prevents shield body 50 from axially slidingcompletely out of housing 12 through opening 30.

The housing 12 and the shield 14 may further include locking structureextending therebetween, for maintaining the shield 14 in fixed relationto the housing 12 after activation. For example, shield body 50 mayinclude structure at the rearward end 54 for frictional engagement, orfor inter-fitting engagement, with the main body 20 or rear cap 24. Forexample, shield body 50 may include locking fingers 59 extending at therearward end 54 thereof, for inter-fitting engagement with lockingrecesses 29 within the interior surface of rear cap 24.

Lancet device 10 further includes a lancet structure 70 disposed withinthe housing 12, and extending through shield 14. As shown in FIGS.7A-7F, lancet structure 70 includes a puncturing element, shown in theform of lancet 72 defining a puncturing end 74 at the forward endthereof. Lancet structure 70 is adapted for axial or longitudinalmovement through the internal cavity 56 of the shield body 50 between aninitial armed position with the puncturing end 74 maintained within theshield body 50 to a puncturing position in which the puncturing end 74extends beyond the forward opening 60 of shield body 50, as will bediscussed further herein in terms of use of the lancet device 10.

Puncturing end 74 is adapted for puncturing the skin of a patient, andmay define a pointed end, a blade edge, and the like. Puncturing end 74may include a preferred alignment orientation, such as with a pointedend of a blade aligned in a specific orientation. In such an embodiment,shield body 50 and/or main body 20 of housing may include target indiciacorresponding to the alignment orientation of the puncturing end 74.Indentations 62 of the shield body 50 and/or indentations 42 of the mainbody 20 may function as such an alignment orientation.

Lancet structure 70 further includes a carrier element 76 supportinglancet 72 at the rearward end thereof. The carrier element 76 and shieldbody 50 may include corresponding guiding surfaces for guiding thelancet structure 70 therethrough. For example, carrier element 76 mayinclude a guide tab 78 on an external surface thereof, with the shieldbody 50 including a corresponding guide channel 80 extendinglongitudinally along an inner surface thereof for accommodating guidetab 78 slidably therein. Desirably, carrier element 76 includes a pairof guide tabs 78 on opposing lateral sides thereof, and shield body 50includes a corresponding pair of guide channels 80 extending alongopposing inner surfaces thereof corresponding to each of the guide tabs78. It is contemplated that the arrangement of the guide tabs andchannels may be reversed, and other guiding surfaces may also be used.The guide tabs 78 and guide channels 80 ensure that the lancet structure70 is properly aligned within shield body 50, and provide for slidingaxial movement of the lancet structure 70 within the shield body 50 andmay prevent or resist rotational movement. A bottom surface 81 of theguide tabs 78 provides an abutment surface for abutting against a bottomsurface of guide channels 80 to prevent the lancet structure 70 fromaxial movement entirely out of shield body 50 through forward opening60.

As shown in FIG. 10, retaining hub 90 is further provided, shown at therearward end 54 of the shield body 50. Retaining hub 90 is desirablyprovided as a separate structure disposed or retained within therearward end of shield body 50. For example, shield body 50 may includestructure for accommodating retaining hub 90, such as recess 68extending within an upper surface of rearward end 54. In this manner,retaining hub 90 rests within recess 68. In other embodiments, shieldbody 50 may include a surface for supporting and positioning retaininghub 90 to assist in assembly. Still in other embodiments of theinvention, functional elements of the retaining hub 90 may be molded orformed directly onto the shield body 50.

Retaining hub 90 defines a lever structure for retaining the lancetstructure 70 in an initial armed position retracted within housing 12.In particular, as shown in FIGS. 8A-8D, retaining hub 90 includes apivotal lever element 92, including a shoulder 94 and a contact surface96 on the upper surface thereof, with a pivot hinge 98 on the lowersurface thereof between the shoulder 94 and the contact surface 96. Asan example, lever element 92 defines a class 1 lever, in which thefulcrum or pivot point is positioned between the force and the load, asin a seesaw. For example, the upper surface of lever element 92 includesthe shoulder 94 opposite the contact surface 96, with pivot hinge 98providing a fulcrum between the shoulder 94 and the contact surface 96.In this manner, the load, represented by the lancet structure 70 restingon the shoulder 94, is separated from the force, which is applied at thecontact surface 96 as will be described in more detail herein, with thefulcrum of pivot hinge 98 located between the force and the load.

As depicted in FIGS. 8A-8D, lever element 92 may be provided, in oneembodiment, as a pivotal generally wedge-shaped structure, with thebottom point of the wedge acting as the fulcrum at pivot hinge 98 forpivotal movement of the lever. The retaining hub 90 may include anannular rim 100, with at least one lever element 92 supported on andpivotally hinged to the annular rim 100 through the pivot hinge 98.Retaining hub 90 typically includes a pair of lever elements 92pivotally hinged to the upper surface of the annular rim 100 at opposingsides thereof. Annular rim 100 is depicted herein as a generallyrectangular ring-like structure with curved corner connections,extending circumferentially or perimetrically to define an interioropening. The term “annular” as used herein is intended to encompass anyring-like or band-like structure, whether circular, curved, orpolygonal, including curved or angular corner connections. It is alsocontemplated that other annular yet incomplete rings or band-likestructures may be used, such as a structure similar to a slotted orslip-on washer, which has a discontinuous annular structure.

Retaining hub 90 and lancet structure 70 are in interference engagementwith each other, such that retaining hub 90 retains the lancet structure70 in an initial armed position retracted within housing 12. Forexample, carrier element 76 may include a finger 82 extending laterallytherefrom, including a support surface 83 on a bottom surface of thefinger 82. Support surface 83 of finger 82 rests on shoulder 94 of leverelement 92, thereby providing interference engagement between the lancetstructure 70 and the retaining hub 90.

Moreover, contact surface 96 of lever element 92 is adapted forcontacting engagement with structure within housing 12. For example,rear cap 24 of housing 12 may include structure extending therein, suchas internal contact 46 integrally formed and extending on at least one,and desirably on two opposing inner sidewalls thereof. Each internalcontact 46 includes an engagement surface 47 for contacting engagementwith contact surface 96 of lever element 92, forming a cam surface. Inone embodiment, contact surface 96 includes a generally rod-shapedportion 97, and the internal surface of rear cap 24 includes a pair ofinternal contacts 46 extending adjacent each other on the inner wallsurface, and on each opposing side of the inner wall surface. In thismanner, the pair of internal contacts 46 engages opposing ends of therod shaped portion 97 of contact surface 96, thereby providing acontinual cam-like contact surface around the perimeter of the rodshaped portion 97 during pivotal movement of lever element 92. In analternate embodiment shown in FIG. 8E, contact surface 96 may includeangular surfaces 197 forming a chamfered portion as opposed to thegenerally rod-shaped portion discussed above. Such a chamfered portionformed by angular surfaces 197 is particularly useful in moldingoperations for forming of the retaining hub 90 in conventional injectionmolding procedures. With such an embodiment, the pair of internalcontacts 46 within rear cap 24 engages opposing ends of the chamferedportion formed by the angular surfaces 197 of contact surface 96,providing for a cam-like contact surface as noted above.

Moreover, lever element 92 is typically positioned on one side of aplane, shown in FIG. 8D at plane Y, dissecting the annular rim 100 at across section to the general longitudinal axis A which generally definesthe lancet device 10 and the direction of travel of lancet structure 70.In this manner, the fulcrum, such as that defined through pivot hinge98, represents a low area moment of inertia above the plane Y, such asat the top surface of annular rim 100, to cause plastic deformation oflever element 92, and namely pivot hinge 98, as the lever element 92pivots outwardly. Such plastic deformation may be permanent, such thatafter the lever elements pivot, they maintain their shape and position.

Movement of the lancet structure 70 through the lancet device 10 isachieved through a biasing force provided through a drive spring 102.Drive spring 102 is adapted to exert a biasing force against lancetstructure 70 to drive lancet structure 70 through the device toward thepuncturing position, and may be disposed between the rearward end of thehousing 12 and the lancet structure 70. Drive spring 102 may be aseparate element contained between the rearward end of housing 12 andthe lancet structure 70, or may be integrally formed with one or both ofhousing 12 and/or lancet structure 70. Rear cap 24 may include structurefor alignment of and/or for maintaining drive spring 102 in the properorientation. For example rear cap 24 may include an alignment nub 104for accommodating the drive spring 102. The lancet structure 70 may alsoinclude a surface or structure for accommodating an opposing end of thedrive spring 102, such as a rear nub 86 extending from the carrierelement 76 of lancet structure 70. Drive spring 102 extends betweenalignment nub 104 of rear cap 24 and rear nub 86 of carrier element 76.When the lancet structure 70 is in an armed position, the drive spring102 exerts a force against the lancet structure, such as between therearward end of housing 12 and the lancet structure 70, biasing thelancet structure 70 toward the puncturing position. The shield body 50and lever element 92 may include inter-engaging structure to preventlever element 92 from pivoting in a reverse direction about pivot hinge98, regardless of the biasing force applied against lancet structure 70and shoulder 94 through drive spring 102. For example, bottom angledsurfaces 99 formed from the wedge-shaped lever element 92 may engage andabut corresponding angled nibs 55 on the rearward end 54 of shield body50. Such inter-engaging surfaces prevent any applied force from drivespring 102 from pivoting the lever element 92 about pivot hinge 98 in areverse direction, that is in a direction such that shoulder 94 pivotsdownwardly into interior cavity 56 of shield body 50. Optionally or inaddition thereto, the plastic deformation of pivot hinge 98 as discussedabove may be permanent, thereby preventing lever element 92 fromautomatically pivoting in a reverse direction to enable the lancetstructure 70 to be re-set in a pre-actuation state resting on shoulder94 after actuation.

A retraction spring 110 may further be provided at the forward end ofthe lancet device 10, for retracting the lancet structure 70 within theshield body 50 after the lancet structure 70 is axially moved to thepuncturing position. Retraction spring 110 typically extends between aforward surface 88 of the carrier element 76 of lancet structure 70 andan inner surface within the forward end wall 58 of the shield body 50.Retraction spring 110 is typically a compression spring, capable ofstoring energy when in a compressed state.

Lancet device 10 may further include a protective cover 120 forprotectively covering the lancet device 10 prior to use thereof. Theprotective cover 120 may include a tab member 122 associated with theforward end of the lancet device 10, which maintains sterility of theforward end wall 58 of shield body 50. Referring to FIGS. 9A-9F, tabmember 122 may include a forward tab portion 124 and a depending skirt126. The depending skirt 126 is adapted to cooperate with the forwardend 52 of the shield body 50, generally encompassing or enclosing theforward end 52. The depending skirt 126 also contacts the forward end 22of the main body 20 of the housing 12. In this manner, the tab member122 encloses forward opening 30 of main body 20 and forward opening 60of shield body 50. Moreover, such arrangement maintains the respectiveforward ends of main body 20 and shield body 50 in fixed relation withrespect to each other, thereby preventing movement therebetween whichcould cause premature activation of the lancet device 10.

A portion of the protective cover 120 may extend within the shield body50 to encompass at least a portion of the puncturing element. Forexample, as shown in FIG. 11D, a post portion 130 extends throughforward opening 60 of shield body 50 and into internal cavity 56thereof, protectively surrounding and encompassing at least a portion ofthe puncturing element, namely lancet 72. The post portion 130 and tabmember 122 may be separate elements which are affixed or otherwisemaintained together. For example, tab member 122 may include an inneropening for accommodating post portion 130 therethrough. Referringgenerally to FIGS. 7A-7E, post portion 130 may be formed integrally withcarrier element 76 of lancet structure 70, completely encompassinglancet 72, thereby maintaining sterility thereof prior to use. Postportion 130 and carrier element 76 may include a notched portion 132 ata juncture therebetween, providing a fraction point for removing postportion 130 and exposing lancet 72. Alternatively, the post portion 130may be secured directly to the lancet 72 by methods customary in themedical field, such as with a releasable medical grade adhesive.

In one embodiment, the rear cap 24 and the housing body 20 are separatestructures which are mated, with the housing body 20 forming a forwardportion of the housing 12 and the rear cap 24 forming a substantial rearportion of the housing 12. More particularly, the rear cap 24 mayconstitute a significant portion of the housing 12, such asapproximately half of the housing 12, mating with the housing body 20 ata location dividing housing 12 approximately in half when measured bythe complete longitudinal length of the housing and rear cap together.Such an arrangement provides for simplified assembly of the lancetdevice 10, in that the internal components including shield 14, lancetstructure 70, and the retaining and engaging elements includingretaining hub 90, drive spring 102 and optionally retraction spring 110,may be inserted within the housing body 20 from the rearward endthereof, requiring little clearance provided by the small size ofhousing body 20 for insertion. Additionally, after inserted as such,such internal elements may be easily seen due to the low clearanceprovided by the relative small size housing body 20 with respect to theoverall housing 12, thereby permitting easy visual assurance of properalignment. Moreover, the rear cap 24 may then be fitted to housing body20 at a location adjacent the internal functional components, such as ata location substantially peripheral to the retaining hub 90 within thehousing 12. Also, the housing body 20 and the rear cap 24 may mate at asubstantial midpoint of the total length of the housing 12, with eachsubstantially defining a half portion of the housing 12. In this manner,the mating of the housing body 20 and the rear cap 24 substantiallyintersects or bisects the finger grip indentations 37, 38.

The respective elements of the lancet device of the present inventionare all typically formed of molded plastic material, such as a medicalgrade plastic material. The lancet 72 may be constructed of any suitablematerial adapted for puncturing the skin, and is typically a surgicalgrade metal such as stainless steel.

Use of the lancet device 10 will now be described with general referenceto FIGS. 1-18, and particular reference to FIG. 11D and FIGS. 12-18.Prior to use, lancet device 10 is provided as shown in FIGS. 1 and 11D,with protective cover 120 covering shield 14 at the forward end thereof.Lancet device 10, and in particular lancet structure 70, is in aninitial pre-actuation state, with finger 82 of carrier element 76abutting or resting upon shoulder 94 of the lever element 92 ininterference engagement therewith. In this manner, lever element 92 ofthe retaining hub 90 maintains lancet structure 70 in this pre-actuationposition within housing 12, and in particular with puncturing end 74maintained retracted within shield body 50. Further, drive spring 102extends between the lancet structure 70 and the rear cap 24 of housing12. In this pre-actuation position, drive spring 102 may be in a relaxedstate or may be in a fully compressed state. More desirably, drivespring 102 is in a partially compressed state in this pre-actuationposition, exerting a biasing force between rear cap 24 and lancetstructure 70, with the interference engagement between finger 82 andshoulder 94 maintaining lancet structure 70 against any such biasingforce. Moreover, the inter-engaging surfaces between bottom angledsurfaces 99 and angled nibs 55 prevent lever element 92 from pivoting ina reverse direction, thereby forcing lancet structure 76 through shieldbody 50. Also, in this state, protective cover 120 prevents any axialmovement of shield 14 with respect to housing 12, thereby preventingactuation of the lancet device 10.

To prepare the lancet assembly for use, the user grasps housing 12, suchas between a finger and thumb on opposing sides 35, 36, and removes theprotective cover 120 from the forward end as shown in FIG. 2, therebyexposing the shield body 50 extending from the forward end of main body20 of housing 12. The forward tab portion 124 of the tab member 122 maybe ergonomically formed, such as through the inclusion of apaddle-shaped member, to allow the user to easily manipulate the tabmember 122 and apply the necessary force or torque to release thedepending skirt from frictional engagement with the forward end of theshield body 50, and to break the post portion 130 from the carrierelement 76 at the notch 132 to thereby release the post portion 130 fromthe lancet 72. The applied breaking force is in accordance with thepresent invention and may be a singular twisting or pulling motion, or acombined “twisting” (i.e. rotational) and “pulling” motion applied forbreaking the connection between the post portion 130 and the carrierelement 76, as well as to release the frictional engagement between thedepending skirt 126 and the shield body 50.

The forward end wall 58 of shield body 50 may then be contacted with alocation on the user's body or another person's body where it is desiredto initiate blood flow, such as the patient's skin surface S as shown inFIG. 13. If provided, target indicia, such as indentations 62, may bealigned with the desired location of puncture.

Once placed against the body, the user exerts a downwardly directedforce on the housing 12 forcing shield body 50 against skin surface S.In particular, the user applies a force against the finger gripindentation 39 of the rear cap 24 in the direction of Arrow X, therebyapplying a force against the skin surface S. Such force establishes anopposing external pressure force between the forward end wall 58 of theshield body 50 and the rear cap 24 of the housing 12 causing the shieldbody 50 to move axially within the housing 12, thereby displacing therearward end 54 of the shield body toward the rear cap 24. Thecorresponding guiding surfaces provided through guide tabs 44 and guidechannels 64 guide the shield body 50 axially through the main body 20 ofhousing 12, ensuring proper axial alignment therebetween.

Since retaining hub 90 is adjacent rearward end 54 of shield body 50,such displacement of the rearward end 54 of the shield body toward therear cap 24 causes corresponding rearward movement of retaining hub 90toward rear cap 24. Moreover, the interference engagement betweenshoulder 94 of lever element 92 of retaining hub 90 and finger 82 ofcarrier element 76 of lancet structure 70 causes corresponding rearwardmovement of lancet structure 70 toward the rear cap 24. Such movementcauses drive spring 102 to compress. In embodiments in which drivespring 102 is in a relaxed state in the initial pre-actuated position,this compressing of drive spring 102 arms drive spring 102 with abiasing force sufficient to propel lancet structure 70 axially forwardthrough shield body 50 to the puncturing position, thereby providinglancet structure 70 in an armed position. At this point, however, lancetstructure 70 is still maintained such that puncturing end 74 isretracted within shield body 50 due to the interference engagementbetween finger 82 and shoulder 94. In embodiments in which drive spring102 is in a partially compressed state in the initial pre-actuatedposition, this compressing of drive spring 102 further arms drivesspring 102 with additional biasing potential energy sufficient to fullypropel lancet structure 70 axially forward through shield body 50 to thepuncturing position. Again, in this pre-actuated armed position, lancetstructure 70 is still maintained such that puncturing end 74 isretracted within shield body 50 based on the interference engagementbetween finger 82 and shoulder 94.

During such axial or longitudinal movement of shield body 50 toward rearcap 24, the retaining hub 90 is also displaced rearwardly (orproximally) toward rear cap 24, with fingers 82 of the carrier element76 resting upon shoulders 94 of the lever elements 92. As shown in FIGS.13-14, such rearward movement of retaining hub 90 causes the camsurfaces of engagement surfaces 47 of the internal contacts 46 withinrear cap 24 to engage and co-act with the corresponding contact surfaces96 of lever elements 92, such as the rod shaped portions 97.Accordingly, the corresponding camming contact surfaces provide anactuator element for the lancet device 10. Such engagement and co-actioncauses the lever elements 92 to pivot about pivot hinges 98 with respectto annular rim 100 due to the wedge-shaped profile of the lever elements92. In particular, with the shoulders 94 extending generally radiallyinwardly of the annular rim 100 and the contact surfaces 96 generally onan external perimeter of the annular rim 100, engagement surfaces 47engage the contacting surfaces 96, and in particular the rod shapedportions 97, at an external perimeter of the annular rim 100, therebypivoting the lever element 92 about the fulcrum of pivot hinge 98 bytipping the contact surfaces 96 and the shoulders 94 to release thelancet structure through the annular rim 100 and into the internalcavity 56 of the shield body 50.

Such engagement provides for actuation of the lancet device. Inparticular, the pivoting of lever elements 92 about pivot hinges 98further displaces shoulders 94 toward the rearward end of rear cap 24,thereby further compressing and further biasing drive spring 102.Continued axial displacement of shield body 50 toward rear cap 24 causesfurther engagement of the corresponding surfaces of internal contacts 46and contact surfaces 96, such that engagement surfaces 47 cam or rideabout the perimeter of rod-shaped portions 97, thereby further pivotinglever elements 92. Eventually, such pivoting causes shoulders 94 to bepivoted to a point at which the interference engagement betweenshoulders 94 and fingers 82 of carrier element 76 is released, as shownin FIGS. 15-16. At this point, fingers 82 are free from shoulders 94 andmay axially move through the internal opening through annular rim 100.The biasing force of drive spring 102 propels lancet structure 70downward away from the rear cap 24 axially through housing 12 and shieldbody 50. During such movement, corresponding guide tabs 78 and guidechannels 80 guide lancet structure 70 axially through shield body 50.Moreover, shield body 50 may further include additional channels inalignment with and adapted for accommodating fingers 82 of lancetstructure 70 in sliding relation during such axial movementtherethrough.

Actuation of the lancet device 10 is therefore achieved through theinterfering or camming engagement contact between the engagementsurfaces 47 and contact surfaces 96, providing the pivoting movement oflever element 92. As noted, such pivoting movement results in bothcompression of drive spring 102 to arm or to further arm the lancetstructure 70 and sequential release of the interference engagementmaintaining the lancet structure 70 in the pre-actuated or armedposition. Accordingly, actuation of the lancet device 10 achievessequential arming and release of the lancet structure through a singlemotion of the device. Moreover, such sequential arming and releasemerely requires movement of the inter-engaging contact surfaces betweenthe housing 12 and the pivoting lever element 92. It is thereforecontemplated that such sequential arming and release may be attainedregardless of whether an axially moveable shield is included, so long assome mechanism for movement of the inter-engaging surfaces with respectto each other is provided.

For example, FIG. 19 depicts a cross-sectional view of a lancet device10 a in an alternate embodiment of the present invention. In thisembodiment, actuation is achieved through an actuator including anactuation element, such as push button 25 a. In particular, housing 12 ais defined by main body 20 a and rear cap 24 a. Push button 25 a extendsthrough housing 12 a at rear cap 24 a, and into the internal cavity 28 atherein. Actuation of lancet device 10 a is accomplished by axiallymoving push button 25 a within housing 12 a, such that one or moreengagement surfaces 47 a at the forward end of push button 25 a withinhousing 12 a contact the corresponding contact surface(s) 96 a of leverelement 92 a, thereby pivoting the lever element 92 a about pivot hinge98 a. As in the aforementioned embodiment, such contacting and pivotingreleases the interference engagement between the support surface 83 a ofcarrier element 76 a and the shoulder 94 a of lever element 92 a,thereby permitting drive spring 102 a to propel lancet 72 a throughhousing 12 a to the puncturing position. Drive spring may be maintainedbetween carrier element 76 a and push button 25 a through alignment nub104 a within push button 25 a. Alternatively, the drive spring may bemaintained between the carrier element and the rearward end of thehousing, with the push button element extending through the housing tocause pivotal actuation.

Returning to the actuation as shown in FIG. 17, the biasing force ofdrive spring 102 propels the lancet structure 70 through shield body 50to a puncturing position, in which puncturing end 74 of lancet 72extends through the forward opening 60 through forward end wall 58 asufficient distance to permit the puncturing end 74 to puncture the skinsurface S. The bottom surface 81 of the guide channels 80 within shieldbody 50 provides an abutment surface for guide tab 78 to prevent thelancet structure 70 from axial movement entirely out of shield body 50through forward opening 60 during such propelling. Moreover, during suchpropelling, the forward surface 88 of carrier element 76 contacts therearward end of retraction spring 110, which is maintained within theforward end 52 of shield body 50, desirably in a relaxed condition inthe pre-actuated and/or armed state of the lancet device. The propellingforce from the bias of drive spring 102 causes such contact withretraction spring 110, thereby compressing retraction spring 110 betweenthe forward surface 88 of lancet structure 70 and the interior of theforward end wall 58 of shield body 50. The structure of retractionspring 110 is designed such that it is compressible, based upon thebiasing force of drive spring 102 propelling lancet structure 70, topermit puncturing end 74 of lancet 72 to extend through forward opening60. Moreover, the retraction spring 110 is a compression spring, and istherefore capable of being compressed in this manner, but includessufficient resiliency to return to a relaxed condition after the lancetstructure 70 extends to the puncturing position. Accordingly, thebiasing force of the compression spring 110 between the forward end wall58 of the shield body 50 and the lancet structure 70 when in a relaxedstate exceeds the biasing force of the drive spring 102 acting betweenthe rear cap 24 of the housing 12 and the rear nub 86 of the lancetstructure 70 after the drive spring drives the lancet structure 70 tothe puncturing position. In this manner, the retraction spring 110 willrelax to an uncompressed state, thus applying a biasing force betweenthe forward surface 88 of the lancet structure 70 and the interiorsurface of the forward end wall 58, thereby forcing the lancet structure70 rearward toward the rear cap 24. Such biasing force retracts thepuncturing end 74 of lancet 72 within the shield body 50 to a positionin which it is shielded from exposure through forward opening 60.Moreover, the opposing forces acting between the drive spring 102 andthe retraction spring 110, and the respective forces of such springsbased on the structure thereof, maintains the lancet structure 70disposed within the housing 12 with puncturing end 74 shielded withinshield body 50, preventing further movement of lancet structure 70 tothe puncturing position.

Moreover, after activation of the lancet device, that is, after thelancet structure 70 is retracted within the housing 12 after thepuncturing position, the shield body 60 and the housing 12 may be lockedin a fixed relation. In particular, with shield body 50 axiallydisplaced toward the rear cap 24, locking fingers 59 may deflect andlock within respective recesses 29, thereby locking shield body 50 in arearward position with respect to rear cap 24 and housing 12. The lancetdevice 10 is therefore safely protected from re-use and may be properlydiscarded, such as in an appropriate medical waste container.

Referring to FIGS. 20-22, the lancet device may include a modifiedversion of a retaining hub 90 i. FIG. 20 shows the retaining hub 90 i aspart of the lancet device 10 as disclosed above, with similar referencenumbers shown in FIGS. 20-22 referring to similar elements described inconnection with FIGS. 1-18. Retaining hub 90 i generally defines anannular shape and is adapted to maintain the lancet structure 70 in aninitial armed position retracted within the housing defined by main body20 and rear cap 24. Retaining hub 90 i typically includes two opposedand elongated support members 91 i connected by two pivotal cam elements92 i to form the annular shape of retaining hub 90 i. Cam elements 92 ieach include two outward-extending shafts 93 i engaged pivotally withthe opposed support members 91 i. Cam elements 92 i each further includeat least one typically wedge-shaped contact element 94 i defining anupper contact surface 96 i on the upper surface thereof. Cam elements 92i each further define a generally centrally located recess or cut-out100 i defined in a bottom side thereof. The purpose of recess 100 i isdescribed herein in connection with the operation of retaining hub 90 iin lancet device 10. As shown in FIGS. 21A and 22, the cam elements 92 idesirably each include two contact elements 94 i disposed generally atopposite ends of the cam elements 92 i , with the recess 100 i definedin the bottom side of the cam elements 92 i between the contact elements94 i.

In the lancet device of this embodiment, retaining hub 90 i and lancetstructure 70 are in interference engagement with each other, such thatretaining hub 90 i retains the lancet structure 70 in an initial armedstate retracted within the housing. For example, fingers 82 on carrierelement 76 may rest on the upper side of cam elements 92 i, therebyproviding interference engagement between the lancet structure 70 andthe retaining hub 90 i. Moreover, upper contact surface 96 i on thecontact elements 94 i may be adapted for contacting engagement withstructure within the housing. For example, rear cap 24 may includestructure extending therein, such as internal contact 46 integrallyformed and extending on at least one, and desirably on two opposinginner sidewalls thereof. As retaining hub 90 i typically includes twocontact elements 94 i on each cam element 92 i, two internal contactssuch as contacts 46 described above may be provided on each of the twoopposing inner sidewalls of the housing. Each internal contact includesa distal engagement cam surface such as cam surface 47 described abovefor contacting engagement with the corresponding contact surface 96 i oncontact elements 94 i.

During usual operation of the lancet device of FIGS. 20-22, axial orlongitudinal movement of shield body 50 toward rear cap 24, causes theretaining hub 90 i to be displaced rearwardly toward rear cap 24, withfingers 82 of the carrier element 76 resting upon the cam elements 92 i.Such rearward movement of retaining hub 90 i causes the contact surfacesof the engagement cam surfaces of the internal contacts within rear cap24 to engage and co-act with the corresponding contact surfaces 96 i onthe contact elements 94 i of cam elements 92 i. Such engagement andcontinued downward or distal movement of the internal contacts causesthe cam elements 92 i to pivot on or rotate about shafts 93 i withrespect to support members 91 i. Due to the generally wedge-shapedprofile of the contact elements 94 i, the pivotal movement of camelements 92 i has the effect of further compressing drive spring 102 byfurther “lifting” fingers 82, at least until the point where rear nub 86on carrier element 76 contacts the inner side of rear cap 24. At thispoint, continued axial or longitudinal displacement of shield body 50toward rear cap 24 pivots cam elements 92 i to a position where recess100 i defined in the bottom side of cam elements 92 i has rotated to aposition generally aligned with fingers 82 at which point theinterference engagement between fingers 82 and cam elements 92 i isreleased by such alignment. The biasing force of drive spring 102 thenpropels lancet structure 70 downward away from the rear cap 24 axiallythrough the housing and through shield body 50 axially through theannular opening defined by retaining hub 90 i.

Referring to FIGS. 23A-23D, a further variation or modification of thelancet device is generally illustrated in a further embodiment. In theembodiment of FIGS. 23A-23D, a puncturing device in the form of lancetdevice 200 is shown. The lancet device 200 generally includes a housing211, a shield 213 received partially within and axially movable relativeto the housing 211, and a skin puncturing assembly 215 (which may besimilar to the lancet structure 70 discussed above) disposed within thehousing 211. The housing 211 is preferably a generally tubular structurehaving a distal end 216 and a proximal end 218, and may include similarstructure to the housing 12 discussed above in connection with FIGS.1-18 including a main body 20 and a rear cap 24. Desirably, the housing211 is open-ended at the distal and proximal ends 216, 218. An end cap240 may be provided at the proximal end 216 of the housing 211 to closethe proximal end 218 of the housing 211. Alternatively, the housing 211may be formed to have a closed proximal end 218 instead of the end cap240. In such an embodiment, the closed proximal end 218 of the housing211 would be integrally formed with the remainder of the body of thehousing 211 in this variation of the puncturing device 200. The skinpuncturing assembly 215 may further include a protective tip guard 282connected to a carrier member 250. The tip guard 282 may be formedintegrally with the body of the carrier member 250, and may include anotched connection with the carrier member 250 in a similar manner aswith protective cover 120 described above.

Flexure members 238 are formed or provided on a proximal end 244 of theshield 213. The flexure members 238 define structure for retaining thelancet structure in an initial armed position retracted within thehousing, acting in a similar manner as the pivotal lever element and theretaining hub of the embodiments previously described in connection withFIGS. 1-19. For example, projections 276 on the flexure members 238extend inward so as to engage or coact with the carrier member 250 ofthe skin puncturing assembly 215. The projections 276 engage or extendinto a circumferential recess 200 defined or formed in the carriermember 250. The recess 210 defines a circumferential edge 212, which isengaged by the projections 276 of the flexure members 238. Theengagement edges 277 of the projections 276 in the lancet device 210illustrated in FIGS. 23A-23D are formed or defined by a radiallyinward-extending tab 214 on each of the projections 276. Engagementedges 277 act in a similar manner as shoulder 94 described above withreference to FIGS. 1-18, with the load represented by the skinpuncturing assembly 215 resting on the engagement edges 277.

The projections 276 maintain the carrier member 250, and thus the skinpuncturing assembly 215, in the retracted position until released ofengagement with the carrier member 250 by axial displacement of theshield 213 into the housing 211. In the pre-actuated state of the lancetdevice 200, the biasing force of the drive spring 270 is restrained bythe projections 276 and by engagement of the distal end 242 of theshield 213 with an interfering structure provided at the distal end 216of the housing 211. In particular, while the shield 213 is axially orlongitudinally movable or displaceable into the housing 211, the shield213 is prevented from moving distally relative to the housing 211 by anedge 217 formed on the shield 213. The edge 217 is formed or defined bya portion 219 of the shield 213 having an increased wall thickness. Theedge 217 coacts or engages with an internal lip 220 formed at the distalend 216 of the housing 211 to restrain the force of the drive spring270. The engagement of the edge 217 with the lip 220 allows the flexuremembers 238 to maintain the carrier member 250 in the retracted positionand restrain the force of the drive spring 270. In particular, in thepre-actuated state of the lancet device 200, the force of the drivespring 270 is transmitted via the projections 276 to the body of theshield 213, which causes the edge 217 on the shield 213 to engage thelip 220 and restrain the force of the drive spring 270.

The flexure members 238 are adapted to be released of engagement withthe carrier member 250 by one or more actuating members 222 (similar tothe internal contact 46 in the embodiment described above with referenceto FIGS. 1-18). The actuating member 222 may be formed integrally withthe end cap 240, or may be formed separately therefrom and secured tothe end cap 240 with, for example, an adhesive. The actuating member 222includes a tapered camming surface 224 (similar to engagement surface47), which is adapted to coact or engage with the tapered cammingsurfaces 278 of the flexure members 238 for actuating the puncturingdevice 200. In particular, to actuate the puncturing device 200 shown inFIGS. 23A-23D, the user, typically a medical practitioner, places thedistal end 242 of the shield 213 in contact with the body part where ablood sample is to be taken, and applies pressure in the direction ofarrow 226 in FIGS. 23A-23D to cause the shield 213 to move proximallyinto the housing 211. The movement of the shield 213 into the housing211 causes the opposing camming surfaces 278, 224 on the flexure members238 and actuating member 222, respectively, to engage and interact. Asthe shield 213 is displaced or moved into the housing 211, the flexuremembers 238 are flexed radially outward due to the interaction of theopposing camming surfaces 278, 224, as shown in FIGS. 23C and 23D. Theflexure members 238 may be adapted or configured to bend or break oncethey are flexed radially outward a preset distance, angle of rotation,or amount. For example, the flexure members 238 may be formed with aweakened area 228, such as a score line, so that the flexure members 238break when flexed radially outward a preset distance or degree ofrotation. Moreover, weakened area 228 may act as a hinge in a similarmanner as pivot hinge 98 described above.

During such movement of the flexure members 238, projections 276 tilttoward the rear end cap 240, thereby “lifting” or moving carrier member250 toward rear cap 240 and compressing or further compressing drivespring 240. Once the projections 276 on the flexure members 238 arereleased of engagement with the carrier member 250, the drive spring 270is free to move the carrier member 250 from the retracted position tothe puncturing position. The drive spring 270 preferably has sufficientstored energy to cause the sharp distal tip 254 of the skin puncturingelement 215 to pierce the skin of a person or animal once the flexuremembers 238 are released of engagement with the carrier member 250.

As the carrier member 250 moves distally and reaches the puncturingposition wherein the sharp distal tip 254 of the skin puncturing element215 is fully exposed, a retraction spring 274 is compressed between thecarrier member 250 and the distal end 242 of the shield 213 in a similarmanner as retraction spring 110 discussed above with reference to FIGS.1-18. The compression of the retraction spring 274 provides a return orretraction force that acts on the carrier member 250 to move the carriermember 250 in a return, proximal, or retraction direction in the housing211, which returns or retracts the skin puncturing element 215 and thesharp distal tip 254 thereof fully into the housing 211 and shield 213.The retraction spring 274 thereafter prevents the reemergence of theskin puncturing element 215 from the housing 211 and shield 213.

While specific embodiments of the lancet device have been described,those skilled in the art may make modifications and alterations withoutdeparting from the scope and spirit of the invention. Accordingly, theabove detailed description is intended to be illustrative rather thanrestrictive. The invention is defined by the appended claims, and allchanges to the invention that fall within the meaning and range ofequivalency of the claims are to be embraced within their scope.

The invention claimed is:
 1. A lancet device comprising: a housingcomprising a forward end and a rearward end; an actuation member atleast partially disposed within the rearward end of the housing, theactuation member adapted for movement relative to the housing; a lancetstructure comprising a puncturing element, the lancet structure disposedwithin the housing and adapted for movement between a pre-actuatedposition wherein the puncturing element is retained within the housingand a puncturing position wherein the puncturing element extends throughthe forward end of the housing; a drive spring disposed between theactuation member and the lancet structure for biasing the lancetstructure toward the puncturing position; and a retaining hub having atleast one lever element pivotal about a fulcrum, the at least one leverelement having a first end in contact with the lancet structure, a freesecond end opposite the first end, and a fulcrum positioned between thefirst end and the free second end, wherein the contact between the firstend of the at least one lever element and the lancet structure retainsthe lancet structure in the pre-actuated position against the bias ofthe drive spring, and wherein movement of the actuation member towardthe forward end of the housing causes an engagement surface of theactuation element to contact the free second end of the at least onelever element to pivot the at least one lever element about the fulcrumand release the first end from engagement with the lancet structure,permitting the drive spring to drive the lancet structure through thehousing toward the puncturing position.
 2. The lancet device as in claim1, wherein the at least one lever element is a class 1 lever.
 3. Thelancet device as in claim 1, wherein the at least one lever elementcomprises a first lever element and a second lever element spaced fromthe first lever element, the first lever element and the second leverelement disposed on opposing sides of the lancet structure.
 4. Thelancet device of claim 1, wherein the retaining hub comprises an annularrim with the at least one lever element pivotally hinged to the annularrim.
 5. The lancet device as in claim 1, wherein the first end of the atleast one lever element comprises a shoulder in interference engagementwith the lancet structure.
 6. The lancet device of claim 1, wherein theat least one lever element comprises a wedge pivotally hinged to theretaining hub forming a pivot hinge defining the fulcrum.
 7. The lancetdevice of claim 1, wherein the lancet structure further comprises acarrier element including a finger in interference engagement with thefirst end of the at least one lever element.
 8. The lancet device ofclaim 1, further comprising a shield extending through the forward endof the housing, with the retaining hub in contact with a rearward end ofthe shield.
 9. The lancet device of claim 1, further comprising aretraction spring for retracting the lancet structure within the housingafter the drive spring drives the lancet structure toward the puncturingposition.
 10. The lancet device of claim 1, further comprising a lancetcover removably covering the puncturing element of the lancet structure.11. A lancet device comprising: a housing having a rearward end and aforward end; a shield at least partially disposed within the forward endof the housing, the shield adapted for movement relative to the housing;a lancet structure comprising a puncturing element, the lancet structuredisposed within the housing and adapted for movement between apre-actuated position wherein the puncturing element is retained withinthe housing and a puncturing position wherein the puncturing elementextends through the forward end of the housing; a drive spring disposedbetween the rearward end of the housing and the lancet structure forbiasing the lancet structure toward the puncturing position; and aretaining hub having at least one lever element pivotal about a fulcrum,the at least one lever element having a first end in contact with thelancet structure, a free second end opposite the first end, and afulcrum positioned between the first end and the free second end,wherein the contact between the first end of the at least one leverelement and the lancet structure retains the lancet structure in thepre-actuated position against the bias of the drive spring, and whereinmovement of the shield toward the rearward end of the housing causes thefree second end of the at least one lever element to contact an internalcontact within the housing to pivot the at least one lever element aboutthe fulcrum and release the first end from engagement with the lancetstructure, permitting the drive spring to drive the lancet structurethrough the housing toward the puncturing position.
 12. The lancetdevice as in claim 11, wherein the at least one lever element is a class1 lever.
 13. The lancet device as in claim 11, wherein the at least onelever element comprises a first lever element and a second lever elementspaced from the first lever element, the first lever element and thesecond lever element disposed on opposing sides of the lancet structure.14. The lancet device of claim 11, wherein the retaining hub comprisesan annular rim with the at least one lever element pivotally hinged tothe annular rim.
 15. The lancet device as in claim 11, wherein the firstend of the at least one lever element comprises a shoulder ininterference engagement with the lancet structure.
 16. The lancet deviceof claim 11, wherein the at least one lever element comprises a wedgepivotally hinged to the retaining hub forming a pivot hinge defining thefulcrum.
 17. The lancet device of claim 11, wherein the lancet structurefurther comprises a carrier element including a finger in interferenceengagement with the first end of the at least one lever element.
 18. Thelancet device of claim 11, further comprising a shield extending throughthe forward end of the housing, with the retaining hub in contact with arearward end of the shield.
 19. The lancet device of claim 11, furthercomprising a retraction spring for retracting the lancet structurewithin the housing after the drive spring drives the lancet structuretoward the puncturing position.
 20. The lancet device of claim 11,further comprising a lancet cover removably covering the puncturingelement of the lancet structure.